Safety container for explosive powder

ABSTRACT

A container for a volume of explosive powder is provided with a volumetric void within the mass of the powder in the area thereof capable of creating a burning rate equal to the mass detonation rate of the powder upon ignition of the powder. The void is formed by a volumetric member positioned within the mass of the powder, the member being arranged so as to prevent powder from sifting into the void. The void provides a volume for accumulation of combustion gases sufficient to prevent the gas pressure within a burning mass of powder from increasing to the point wherein the mass detonation rate of the powder mass is reached. Thus the ignited mass of powder merely burns itself up without detonating.

United States Patent [191 Shansey Jan. 30, 1973 [54] SAFETY CONTAINER FOR EXPLOSIVE POWDER [75] Inventor: John W. Shansey, Alton, Madison,

Ill.

[73] Assignee: Olin Corporation [22] Filed: June 25,1971

[21] Appl. No: 156,697

[52] US. Cl. ..86/1, l02/24 R [51] Int. Cl ..F42b 33/00 [58] Field of Search .....86/1, 20, 20 C; 102/24 R, 97,

Primary Examiner-Verlin R. Pendegrass Attorney-Donald R. Motsko et al.

[57] ABSTRACT A container for a volume of explosive powder is provided with a volumetric void within the mass of the powder in the area thereof capable donating a burning rate equal to the mass detonation rate of the powder upon ignition of the powder. The void is formed by a volumetric member positioned within the mass of the powder, the member being arranged so as to prevent powder from sifting into the void. The void provides a volume for accumulation of combustion gases sufficient to prevent the gas pressure within a burning mass of powder from increasing to the point wherein the mass detonation rate of the powder mass is reached. Thus the ignited mass of powder merely burns itself up without detonating.

7 Claims, 4 Drawing Figures SAFETY CONTAINER FOR EXPLOSIVE POWDER This invention concerns the prevention of detonation of a charge of explosive powder within a relatively large volume container which would otherwise result from deflagration of the powder within the container.

In the manufacture of explosive or incindiary devices such as certain types of ammunition, and the like, large quantities of explosive material, such as smokeless powder and the like, must frequently be stored, or transferred from place to place in sizeable containers. Large containers, hoppers, or bins may be used to ship the explosive powder or may be used on assembly lines of the devices being produced.

Storage and shipment of such large volumes of such detonatable explosive material is, of course, dangerous since ignition of the stored volumes can result in detonation thereof with catastrophic results. This danger requires utmost precautions being taken in the storage areas, such precautions including the abolition of smoking, matches, lighters, and other devices which could cause ignition of the stored powder charges.

Notwithstanding such safety precautions, accidental explosions may still occur as a result of sparks caused by metal parts being dropped, defective electrical wiring, heat generated by friction in working mechanisms, accidents during shipment, and myriad other causes which the most stringent safety precautions can minimize, but not eliminate.

This invention concerns the prevention of detonation of a stored volume of explosive material even if deflagration within the stored volume occurs. It is known that detonation of a confined mass of explosive powder will occur once heat and gas pressure (caused by combustion gases produced by the burning powder) become sufficient to cause the burning rate of the powder to reach a mass detonation rate, at which time all of the powder is substantially instantaneously consumed, causing an explosion. If the stored po'wder burns at a rate which is less than the mass detonation rate, no explosion will occur, and the powder will merely burn itself up. The mass detonation rate of a particular powder varies with the composition of the powder, certain powders being fast burning, and other powders being slow burning. This invention provides for the placement of a void in the critical area of the powder mass at which area the mass detonation rate can be reached because of the insulating qualities of the surrounding powder mass, the void serving as a space into which pressure and heat will diffuse quickly enough to prevent detonation. Thus the burning powder will merely burn itself up without detonating.

The void can be formed by positioning a volumetric hollow body within the powder mass proximate to the critical area of the powder mass. The volumetric body is arranged so as to ensure that powder from the mass will not be able to leak into the void. The volumetric body can be any of a number of different configurations, and can be made ofa readily combustible material, such as paper, plastic, wood, or the like. The volumetric body can be closed, sealed hollow body within the powder mass in the case of shipping containers which may be shifted in position during shipping, or the volumetric body may be umbrella-like, in the case ofa storage container having a fixed relative position. The volumetric body can be held in position within the container by being fastened to the walls of the container, or can be held in position merely by the surrounding powder mass into which it is embedded.

It is, therefore, an object of this invention to provide a system having a volumetric void within a mass of detonatable material'proximate to the critical area of the mass at which area combustion of the mass can result in detonation of the material, the void providing for diffusion of combustion pressure and heat sufficient to prevent detonation.

It is a further object of the invention to provide a system of the character described wherein the void is formed by a volumetric body positioned within the mass of detonatable material.

It is yet another object of the invention to provide a system of the character described wherein the volumetric body is hollow, and is formed from a readily ignitable material.

These and other objects and advantages of the invention will become more readily apparent from the following detailed'description of several preferred embodiments of the invention taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a side sectional view of a powder hopper formed in accordance with the prior art and used for storing and dispensing of large volumes of explosive powder;

H0. 2 is a side sectional view of a powder hopper similar to that shown in FIG. 1, but having a void volume within the powder mass proximate to the critical area thereof;

FIG. 3 is a perspective sectional view of a shipping container for large volumes of explosive powder, the container having a void volume within the powder mass in the critical area thereof; and

FIG. 4 is a side sectional view of another embodiment of a shipping container having a volumetric void therein extending through the entire length of the container.

Referring now to FIG. 1, there is shown a sectional view of a conventional Kingsmill powder hopper used for storing and dispensing comparatively large volumes of explosive powder. The hopper 2 includes a cylindrical side wall 4 and a frustoconical bottom wall 6 opening into an exit chute 8. A cap member 10 is fitted onto the exit chute 8 and includes a valve 12 (shown schematically) through which powder from the contained charge 14 is fed. A plurality of supports 16 hold the hopper 2 above a surface 18 such asthe ground or a floor. The top of the hopper 2 is open to the atmosphere, as at 20. Additional powder is fed into the hopper 2 through openings 22 in the sidewall 4. It has been found that if burning of the powder occurs in the area marked X, generally near the apex of the bottom wall 6, detonation will occur because of the insulating of pressure and heat resulting from the surrounding powder mass. The area marked X is thus the critical area of the powder mass wherein the mass detonation rate of the powder can be reached ifburning occurs there.

Referring now to FIG. 2, the Kingsmill hopper 2 has been modified to include a preferred embodiment of the invention. A volumetric body 24 is positioned within the powder mass 14 proximate to the critical area X of the powder mass. The volumetric body 24 is in the form of an inverted cone, and is fixedly positioned within the hopper by means of struts 26 secured to the side wall 4 of the hopper. it will be understood that while the body 24 is shown as being an inverted cone, it could be any of a number of other shapes or configurations so long as it forms a volumetric void 28 within the powder mass 14. The body 24 can be made of metal, or it can be made of a readily combustible material, such as paper, plastic, treated fiber, or the like. The body 24 can also be made in a closed geometric configuration, such as a sphere, or the like, with the void 28 being completely container within the body 24, provided that the body is made ofa readily combustible material so that, upon ignition, the wall of the body will burn enough to open the void to receive combustion gases from the burning powder. Thus, the void 28 provides a free space into which combustion gases and heat from the burning powder can diffuse to prevent a build up of pressure and heat within the burning mass of powder. Prevention of heat and pressure build up permits the powder to burn at a rate which is less than the mass detonation rate thereby avoiding detonation of the powder mass.

Referring now to FIGS. 3 and 4, there is shown a typical shipping container 30 having therein a preferred embodiments of the invention. The container 30 is preferably formed of cardboard or some other readily combustible material, and is preferably cylindrical in shape. The containe. 30 contains a mass of explosive powder 32. In FIG. 3 there is shown an embodiment of the invention including a cubical volumetric member 34 which is positioned within the container 30 approximately in the center of the powder mass 32. The member 34 is held in place by the surrounding powder and defines a free volume within the powder mass 32. The volumetric member 34 is preferably made of paper, but may be made of plastic, treated wood, or some other fast burning material. The member 34 is sealed so that powder cannot seep into the void 36, since the void 36 must be kept free for receiving expanding combustion gases.

FIG. 4 discloses another embodiment of the invention preferred for use with a shipping container. The container 30 contains a mass of explosive powder 32, and also a cylindrical volumetric member 38. The end walls 31 of the container 30 combine with the volumetric member 38 to provide a free space 40 within the powder mass 32. The free space 40 is centrally located within the powder mass 32 and extends axially from one end of the container 30 to the other. The member 38 is made of a fast burning material such as paper, plastic, or the like, as are at least the end walls 31 of the container 30.

It will be readily appreciated that volumes of detonatable powder can be safely stored by the use of containers having free volumes proximate to the critical area of the powder mass wherein attainment of the mass detonation rate of the powder is possible. The free volumes serve to receive combustion gases and heat from the burning area of the powder mass, thereby preventing pressure and heat build-up which is necessary for the mass detonation rate of burning of the powder to be reached. The free volume is provided in the container by means of a volumetric member having ticed since the volumetric members can be made of paper, or other inexpensive material, and presently available containers can be easily modified in accordance with the teachings of the invention.

Since many changes and variations of the disclosed embodiments of the invention may be made without departing from the inventive concept, it is not intended to limit the invention otherwise than as required by the appended claims.

What is claimed is:

l. A container for holding a volume of smokeless powder material sufficiently large to contain a critical area wherein ignition of the material can result in attainment of the mass detonation rate of the material, said container including an interior wherein the volume of material is disposed; and means in said interior of said container operative to form a volumetric void proximate to the critical area of the volume of material, said volumetric void being operative to receive combustion heat and gas after ignition of the material in the critical area to prevent attainment of the mass detonation rate of burning of the material.

2. A package comprising:

a. a container;

b. a volume of smokeless powder material in said container, said volume being sufficiently large to contain a critical area wherein ignition of the material can result in attainment of the mass detonation rate of burning of the material; and

c. volumetric means in said volume of material, said volumetric means being operative to provide a volumetric void proximate to said critical area whereby said void can receive combustion heat and gas to prevent attainment of the mass detonation rate of burning of the material.

3. A package comprising:

a. container means;

b. a volume of smokeless powder material in said container means, said volume being sufficiently large to have a critical area wherein ignition of the material can result in attainment of the mass detonation rate of burning of the material; and

c. hollow volumetric body mean positioned within said volume of material and forming a volumetric void proximate to said critical area of said material whereby said void can receive combustion gas and heat to prevent attainment of the mass detonation rate of burning of the material.

4. The package of claim 3, wherein said body means is formed from a fast burning substance, and is operative to seal said void against leakage of said material.

5. The package of claim 3, wherein said body means is secured to said container means and held in a fixed position therein.

6. The package of claim 3 wherein said body means is an open ended tubular member having its ends closed by opposite sides of said container means.

7. The package of claim 3, wherein said body means is held in place by being surrounded by said material. 

1. A container for holding a volume of smokeless powder material sufficiently large to contain a critical area wherein ignition of the material can result in attainment of the mass detonation rate of the material, said container including an interior wherein the volume of material is disposed; and means in said interior of said container operative to form a volumetric void proximate to the critical area of the Volume of material, said volumetric void being operative to receive combustion heat and gas after ignition of the material in the critical area to prevent attainment of the mass detonation rate of burning of the material.
 1. A container for holding a volume of smokeless powder material sufficiently large to contain a critical area wherein ignition of the material can result in attainment of the mass detonation rate of the material, said container including an interior wherein the volume of material is disposed; and means in said interior of said container operative to form a volumetric void proximate to the critical area of the Volume of material, said volumetric void being operative to receive combustion heat and gas after ignition of the material in the critical area to prevent attainment of the mass detonation rate of burning of the material.
 2. A package comprising: a. a container; b. a volume of smokeless powder material in said container, said volume being sufficiently large to contain a critical area wherein ignition of the material can result in attainment of the mass detonation rate of burning of the material; and c. volumetric means in said volume of material, said volumetric means being operative to provide a volumetric void proximate to said critical area whereby said void can receive combustion heat and gas to prevent attainment of the mass detonation rate of burning of the material.
 3. A package comprising: a. container means; b. a volume of smokeless powder material in said container means, said volume being sufficiently large to have a critical area wherein ignition of the material can result in attainment of the mass detonation rate of burning of the material; and c. hollow volumetric body mean positioned within said volume of material and forming a volumetric void proximate to said critical area of said material whereby said void can receive combustion gas and heat to prevent attainment of the mass detonation rate of burning of the material.
 4. The package of claim 3, wherein said body means is formed from a fast burning substance, and is operative to seal said void against leakage of said material.
 5. The package of claim 3, wherein said body means is secured to said container means and held in a fixed position therein.
 6. The package of claim 3 wherein said body means is an open ended tubular member having its ends closed by opposite sides of said container means. 